2) The volume of a fixed mass of a gas is27.5cm³ at a pressure of 40.5mmHg.Calculate its pressure if the volume is doubled given that the temperature is constant.
Step I
From Boyle's law, P V =P V at a constant temperature

Step II
P1=40.5mmHg, V1=27.5cm , V2=55.0cm , P2 is unknown
Step III
To calculate the unknown final pressure P , substitute the values in P1V1=P2V2
        

Step IV
Make P2 the subject of the formula
P1V1=P2V2